Clutch control mechanism



June 13, 1950 Original Filed Nov. 20, 1943 H. w. PRICE 2,511,373

CLUTCH CONTROL MECHANISM 3 Sheets-Sheet 1 June 13, 1950 H. w. PRICE 2,511,373

CLUTCH CONTROL MECHANISM Y Original Filed Nov. 20, 1943 3 Sheets-Sheet 2 INVENT R HA/EOLD W PE/CE June 13, 1950 H. w. PRICE 2,511,373

CLUTCH CONTROL MECHANISM Original Filed Nov. 20, 1943 3 Sheets-Sheet 3 INVENTUE meow W F/a/cf Patented June 13, 1950 UNITED STAT CLUTCH CONTROL MECHANISM Harold W. Price, Bradenton, Fla., assignor to Bendix Aviation Corporation, South Bend, Ind., a

corporation of Delaware Original application November 20, 1943, Serial No. 511,085. Divided and this application April 30, 1945, Serial No. 591,098

4 Claims. (Cl. 192-91) ES PATENT OFFICE and engagement of a friction clutch which is 5 devoid of yieldable means for maintaining the driving and driven members of the clutch in engagement with each other. Such yieldable means is of course one of the principal parts of the conventional friction clutch. In short my invention relates to power means for operating a, friction clutch to effect both an engagement and disengagement of said clutch.

One of the objects of my invention is to provide, in an automotive vehicle comprising 9. vel5 hicle speed responsive governor, a friction clutch devoid of means for engaging the clutch, an accelerator, and a transmission and clutch controlling shift lever, a pressure difierential and spring operated double-acting motor unit operable at the will of the driver, by his operation of the accelerator and shift lever, to effect an operation of the clutch. Yet another object of the invention is to pro vide, in the power plant of an automotive vehicle,

power means for moving the driven element of a friction clutch into and out of engagement with the driving element of said clutch thereby effecting respectively an engagement and dis-.

engagement of said clutch, said power means including a pressure differential and spring operated double-acting motor unit consisting of twoseparate motors and further including valve? means'for controlling the operation of said mo- 1 tor unit, said means including the accelerator operated throttle of the carburetor of the vehicle and further including a three-way valve controlled both by the gearshift lever of the vehicle and a vehicle speed responsive governor.

The principal object of my invention is to pro- 40 vide a friction clutch control mechanism for an automotive vehicle said mechanism including a pressure differential and spring operated motor unit operably connected to a friction clutch of the aforementioned type, said motor unit in.- 40

cluding two separate motors, one of said motors being controlled by an operation of the carburetor throttle valve of the vehicle and operative to effect a so-called first stage of engagement of the clutch and the other motor being controlled by said carburetor throttle valve and by either the shift lever of the vehicle or .a vehicle speed responsive governor and operative to effect a socalled second stage of engagement of the clutch.

This motor unit, which constitutes the invention as 2 of this application, is disclosed in my co-pendin application Serial No. 511,085, filed November 20, 1943, the instant application being a division thereof.

Yet another object of my invention is to provide power means, including a pressure differential and spring operated motor unit, for effecting an engagement of a friction clutch including a driving element and a driven element, said power means further including spring means operative to effect a separation of said clutch elements, that is a disengagement of said friction clutch.

A further object of my invention is to provide power means for effecting a smooth engagement of an automotive friction clutch when the accelerator of the vehicle is suddenly depressed to start the car in motion.

Other objects of the invention and desirable details of construction ofparts will become apparent from the following detailed description of a single embodiment of the invention, taken in conjunction with the accompanyin drawings illustrating said embodiment, in which:

Figure 1 is a diagrammatic view disclosing the features of a friction clutch and a clutch operating power means the motor unit of which constitutes the invention of this application;

Figure 2 discloses in section the clutch operating pressure differential and spring operated motor unit of my invention together with a portion of the valve mechanism for controlling the 7 operation of said unit; and

Figure 3 is a longitudinal sectionalview of the valve mechanism disclosed in Figure 2.

Referring now to Figure 1 disclosing the com-r bined friction clutch and clutch operating power means of my aforementioned parent application Serial No. 511,085, a clutch operating double-acting pressure differential and spring operated motor unit I, constituting my invention, is connected to a friction clutch [2, Figure 1, said clutch being distinguished by the absence of the usual clutch springs. This clutch includes a casing i4 fixedly mounted on the casing of a change speed transmission it said transmission being drivably connected to the drive member iii of the clutch by means including a shaft 20. This driven member of the clutch is provided at its outer periphery with the usual friction mat 22 one face of said mat being movable into engagement with the inner face of a clutch driving member 2 which is drivably connected to the internal combustion engine of the vehicle, not shown. Now the clutch driven member i 8 is preferably so constructed that the mat 22 moves slightly away from the clutch driving member 24 when the clutch operating power means of my invention is rendered operative to disengage the clutch.

Describing now the force transmitting means interconnecting the driven clutch member II with the power elements of motor unit I0, said means includes a connecting rod 26. Figure 2. adjustably connected to a link 20. This link is pivotally connected to one end of one arm of a crank member 30 pivotally mounted. that is fulcrumed, upon a fixedly mounted pin 32. The end of another arm of the crank member 20 is pivotally connected to a link 34 which is adjustably connected to one arm of a lever 20. This lever is fulcrumed upon the rounded end of a stud 38 which is fixedly secured to the clutch casing member I4. The lower arm 39 of the lever 36 preferably lies within a slotted portion 31 of a thrust member 40 sleeved over and slidably mounted upon the shaft 20. A thrust ring 42 mounted on the thrust member 40 is at all times in contact with crank members 44 pivotally mounted upon a clutch housing member 46 secured to the clutch driving member 24. The cranks 44 may be pivotally connected at 45 with a thrust plate 48 contactable with the outer face of the friction mat 22; or the cranks 44 may be in disconnected engagement with said thrust plate thereby permitting the mat 22 to move out of engagement with the driving clutch element 24 when the clutch operating power means of my invention is operative to disengage the clutch.

A tension spring 50 interconnecting the clutch casing I4 and the lever 36 and tension springs 52 interconnecting the cranks 44 and easing 4 Figure 2, of the cup shaped member 68 is one of the principal parts of the motor unit I in its operation of -eifecting an engagement of the clutch.

The motor 56 of the motor unit I0 is controlled in part by a solenoid operated three-way valve member 46 constitute the principal parts of the power means for effecting a disengagement of the clutch that is the movement of the mat 22 of the driven clutch member away from the clutch driving member 24. A foot operated clutch pedal 41, connected to an arm 49 of the crank member 30 by a link 5|, serves as a means to effect a disengagement of the clutch in the event of failure of the springs 52 and the spring 50.

Referring now to Figure 2 disclosing my invention, that is the pressure differential and spring operated motor unit I0, this unit consists of two separate motors, a so-calledflrst stage clutch engaging motor 54 and a clutch engaging 3 motor 56; and as will be described hereinafter the ber 60 together with a diaphragm power element 66 constitutin the motor 54. The casing member 60 and the power element 66 are secured together by bolts 63. The connecting rod 26 is secured to the power element 66 by a nut 65 and the upper portion of said element is telescoped within a hollow rod 60 which is threadedly connected to the hub portion 10 of said power element. The upper end of the connecting rod 26' contacts a compression spring 12 housed within the rod 68, said spring serving to make the connection between the power element H and the driven clutch element a yieldable one. A compression spring 14, interposed between the power element 6| and the bottom, that is upper end,

unit 16 disclosed indetail in Figure 3, said unit comprising casing members I0 and and a disk member 02 detachably secured together by suitable fastenings such as bolts 84. The casing members house a. solenoid including a windin 04 and an armature 88; and a valve member 90 is connected to one end of said armature. As disclosed in Figure 1 the solenoid winding 06 is wiredin series with the ignition switch 92 of the ignition system of the car, a grounded battery 94 and a grounded breaker switch 86. The latter switch is operated by the shift lever 90 of the car said switch, and the force transmitting means interconnecting the switch with the shift lever, being so constructed and the parts thereof so arranged that the switch is closed during the first increment of movement of the shift lever and opened during the last increment of movement of said lever. The winding 8|; is also wired in series with the battery, ignition switch and a grounded vehicle speed responsive governor operated switch I00 therefore it follows that the switches 86 and I00 are in parallel in the electrical circuits. The governor operated switch I00 is closed by the governor when the speed of the car is reduced to or below a certain factor.

Briefly describing the operation of the unit 16 when the solenoid is energized, by either reducing the speed of the car below governor speed or by moving the shift lever to operate the transmission I6, then the valve member 90 is seated to cover an opening I02 in the disk member 02 thereby interconnecting the intake manifold I04. of the engine with a control chamber I06 of the motor 56. Tracing this air transmitting connection the same includes a conduit I00 interconnecting the manifold with the valve unit I6, a duct H0 in said unit, a chamber H2 in said unit, and a conduit II4 interconnecting the chambers I06 and H2. The conduit H4 has incorporated therein aspring and pressure differential operated check valve II6 the operation of which is described hereinafter. When the solenoid of the unit I6 is deenergized a spring H8 within said unit functions to seat the valve member 90 to cover the end of the duct IIO thereby venting the motor chamber I06 to the atmosphere via a port I20 in the unit I6, a chamber I22 in said unit. the opening I0 the chamber H2 and the conduit II4.

Describing now the valve means for controlling the motor 54 and in part controlling the motor 56 the principal part of said valve means is simply the throttle or so-calledbutterfly valve I24 of the carburetor I26 of the vehicle. The other part of this control valve means constitutes a, small part of the body section I28 of the carburetor said part being provided with an opening I30; and this opening registers with one end of a conduit I32. This conduit is connected at its other end with a hollow nipple I34 connected to the casing 60 of the motor 54. When the accelerator, not shown, is completely released to thereby completely close the throttle valve I24 as disclosed in Figure 1 then the edge of said valve adjacent the opening I30 lies below said opening accordingly the gaseous pressure at said opening and within the conduit I32 is atmospheric or substantially so; and it follows therefore that the gaseous pressure within a 54 is then said to be deenerg'ized. Now when the accelerator is depressed to open the throttle valve I24 the aforementioned edge portion of said valve is moved clockwise that is in the direction of the arrow, Figure 1, to a position above the opening I30 resulting in a relatively rapid flow of air through the body section I28 and the venturi effect of this flow of air across the inner end of the opening I30 results in a flow of air through the conduit I32 from the chamber I35 to partially evacuate said chamber. Nowthe degree of vacuum created in the chamber I35 is directly proportional to the rate of flow of air through the body section I28 and incidentally it should be added that this rate of flow of air is determined in large measure by the speed of the engine and v the degree of opening of the throttle valve I24 particularly the former. It follows therefore that the degree of vacuum that is degree of gaseous pressure in the chamber I35 and the consequent clutch engaging force exerted by the power element 66 is either directly proportional or substantially directly proportional to the speed of the engine and the driving clutch element 24 connected thereto. Explaining the creation of this clutch engaging force when the chamber I35 is partially evacuated the motor 54 is energized for the power element 66 is then subjected to a differential of pressures said element being subjected to the pressure of the atmosphere on its upper side via a vent port I36 in the casing member 58 and a pressure less thanatmosphere on its lower side.

Describing now the operation of the above described mechanism, when the car is at a standstill and the internal combustion engine is idling then the clutch is disengaged; for at this time the throttle valve I24 is in its closed position as disclosed in Figure 1 thereby creating, by virtue of the pumping action of the pistons, of the engine, a. partial evacuation of the intake manifold I04. It follows therefore that the control chamber I06 of the motor 56 is likewise partially evacuated inasmuch as the valve member 90 is at the time positioned to interconnect said chamber with the manifold; for it will be remembered that when the car is at a standstill the governor operates to close the switch I00 which results in an energization of the solenoid of the unit 16.

Now when the control chamber I06 is partially evacuated the motor 56 is energized by vacuum resulting in a movement of the power element 6i upwardly to compress the spring I4; and this operation, together with a deenergization of the motor 54, makes possible an operation of the spring 50 and the springs 52 to effect a disengagement of the clutch. As to the deenergization of the motor 54 this is effected as explained above, when the throttle valve I24 is closed.

The clutch having been disengaged by the slight separation of the driving and driven elements of the clutch, the driver will then probably operate the selector lever 98 to establish the transmission I6 in its low gear setting and this having been done he will then depress the accelerator, not shown, to open the throttle valve I24 to effect both a speeding up of the engine and an engagement of theclutch.

however probably does not delay the depression I the throttle valve I24 is opened said motor is energized the degree of said energization being directly proportional to the rate of flow of air past the opening I30. Now inasmuch as the clutch elements are .only slightly separated when the clutch is disengaged it follows that said elements are relatively quickly brought into engagement to start the car in motion; and the acceleration of the car is increased as the loading of the clutch plates is increased with a speeding up of the engine. As described in other words above the clutch plate loading is therefore either directly proportional or substantially directly proportional to the torque of the engine which is of course the operation desired.

When the car speed reaches the so-called governor speed, that is the speed of the car at which the governor operates to open the switch I00, then the second stage of clutch engaging operation of the clutch control mechanism is initiated; for when the switch I00 is opened the solenoid of the unit I6 is deenergized to move the valve member to the position disclosed in Figure 3 thereby admitting atmosphere at a fixed rate into the chamber I06. This fixed rate is effected by an opening I40 in the check valve I I6. The motor 56 is then energized as a result of the expansion of the spring I4 the rate of said expansion, to increase the loading of the clutch members, being constant by virtue of the fixed rate of bleed of air into the chamber I06. There is thus effected the second and final stage of engagement of the clutch to completely load the clutch elements in contact with each other and thereby prevent a slipping of the clutch.

Should the driver depart from a normaloperation of the accelerator by depressing the same very suddenly to its wide open throttle position then the motor 56 becomes the sole means for eifecting the engagement of the clutch; for with such an operation of the accelerator, which is usually efiected in starting the car from rest, the energization if any of the motor 54 is insufficient to effect a loading Of the clutch elements.

The motor 56 is then spring energized to progressively increase the loading of such elements to get the car under way.

Describing this operation in detail with a sudden opening of the throttle the manifold vacuum is suddenly dropped and the gaseous pressure within said manifold increases to atmospheric or substantially so. Air is thus bled into the chamber I06 to effect the aforementioned spring energization of the motor 56, via the connection between the manifold and said chamber it being remembered that with the above operation the check valve H6 is closed as disclosed in Figure 2.

After the vehicle is under way in low gear above governor speed and the desired vehicle speed is reached the driver, to successively disengage the friction clutch and establish the transmission in a higher gear ratio, needs but to first release the accelerator and then move the shift lever to the desired position. As described above the first increment of movement of said lever serves to close the switch 96 thereby effecting a disengagement of the clutch. Then after the transmission is established in gear and the driver removes his hand from the shift lever said removal will, by virtue of the opening of the switch 96, serve to initiate the second stage clutch engaging operation of the motor 56. The driver of the accelerator accordingly the so-called first stage engagement of the clutch is probably well under way or completed before the spring 14 has completed its operation of loading the clutch of the hand from the shift lever after a gear shift movement thereof or an increase in the speed of the vehicle above its governor speed. It is to be particularly noted that a smooth engagement of the clutch is effected inasmuch as with the mechanism of my invention the loading of the driving and driven clutch elements is, with a normal operation of the accelerator, directly proportional to the capacity of the engine, measured by its R. P. M., to drive the driving clutch element. In other words with the clutch control mechanism of my invention the loading of the clutch elements is, with a normal operation of the accelerator, directly proportional to the torque of the engine which of course insures the desired acceleration of the vehicle under tions.

I claim:

1. In an automotive vehicle provided with a friction clutch comprising a driving element and a driven element, power means operative to either make possible a movement of the driven element away from the driving element a relatively short distance or to force the driven element into engagement with the driving element-said power means comprising a spring operative to make possible the firt mentioned operation anda motor unit for effecting the second mentioned operation, said motor unit comprising two separate motors operative to effect this operation in two stages.

2. In an automotive vehicle provided with a friction clutch comprising a driving element and a driven element, power means for moving and controlling the movement of the driven element away from and toward the driving element, said all driving condi- 'power means including yieldable means operative to move the driven elementaway from the driving element, that is effect a disengagement of the clutch, a pressure differential and spring operated motor unit operative to make possible an operation of the yieldable means to effect a disengagement of the clutch and also operative to effect an engagement of the clutch by forcing the driven element into engagement with the driving element, and valve means for controlling the operation of said motor unit.

3. In an automotive vehicleprovided with a friction clutch and a manually operated lever,

power means for effecting both an engagement and a disengagement of said clutch, said power means including a double-acting motor unit comprising two power elements serving, in part, to outline two control chambers, said power elements including two power pistons, valve means, including a manually operated valve member, for controlling the operation of said motor unit, means for operating said valve means comprising a solenoid and means for controlling the operation of the solenoid including a switch operated by the manually operated lever.

4. In an automotive vehicle provided with a friction clutch comprising a driving element and a driven element, spring means operative to make possible a movement of the driven element away from the driving element a short distance to thereby effect a disengagement of the clutch, and

means including a double-acting pressure differential and spring operated motor unit operative to both make possible the aforementioned operation of the spring means and to effect an engagement of the clutch by forcing the driving and driven elements thereof into engagement with each other. 3

HAROLD W. PRICE.

REFERENCES CITED The following references are of record in the file of this patent: 

